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2 Sheets-Sheet 1.

(NoMode1.,)

J. D. FRANCKS.

Process for Preserving Wood. No. 231,419. Fg.1.PatenteCLAzug/.

1 I l l l I I Il .FErEHs. PNOTOMTHGGRAFNER wASMiNGToN, D C

(No Model.) 2 Sheets-Sheet 2. J. D. FRANCES. Process for Preserving Wood. No. 231,419. Flai Patented Aug. 24,1880.

UNITED STATES PATENT OFFICE.

JONAS l). FRANOKS, OF HANOVER, GERMANY.

PROCESS FOR PRESERVING WOOD.

SPECIFICATION forming part of Letters Patent No. 231,419, dated .August 24, 1880.

^ Application filed April 27, 1880. (No model.) Patented in Germany January 20, 1880.

To all whom it may concern:

Be it known that I, JoNAs D. FRANcKs, of Hanover', Germany, have invented an lmproved Process for Treating Vood, of which the following is a specification.

My invention relates to the treatment of Wood for the purpose of increasing its durability and the beauty of its appearance.

It consists, essentially, in impregnating the Wood with a mixture of lime-water and urine. This mixture, applied to the wood in the manner hereinafter described, greatly increases the density7 and solidity of all kinds ot' wood, and at the same time thoroughly chan-ges and improves the original tint, thereby greatly increasing the durability and beauty ofthe Wood, Whatever the variety to which it may be applied.

The mixture specified above maybe applied to the wood in any of the Ways or by means of any ot' the appliances used for like purposes. It is only necessary, rst, that the acids and -resins contained naturally in the wood should be expelled, and that the Wood thus freed from these substances should be saturated With the described mixture.

I have shown two forms of apparatus adapted to effect the saturation of any kind of Wood accordin g to my invention.

0u Sheet l the three igures represent a form of apparatus adapted to be moved readily from place to place and more elaborate in structure. ln these figures a receptacle, A, is shown, adapted to receive the Wood and to be closed tightly by a cover, a. After the Wood has been so inclosed steam is let on through the pipe d at a pressure of about two atmospheres. The application of the steaslnld be`cntinued long enough to extract from the wood the acids, juices, and resins speciiied above. The length of time required for this purpose will vary greatly with the variations in the thickness or kinds of wood. After these substances have been removed by the application of the steam the alkaline liquid or lye is admitted in a heated condition, by cock1 c, into the mixture-receptacle, Which contains a mixture of linie-Water and urine in about equal proportions. The cock c is now shut, the air is exhausted from the receptacle ,A by means of the air-pump B. The cock f is then opened, and in a short time the wood within the recep- 'tacle Will have absorbed the mixture thus adof mixture is forced into the receptacle up to a pressure of from one to four atmospheres.

The amount of pressure andthe length of tlme during which it is maintained must depend upon the quality of the different species of 6o wood under treatment and the form or thickness of the Wood. In like manner the application ofthe Whole process must in practice be varied in accordance with the qualities required of the article to be manufactured, whether it be desired to harden the wood and increase its density throughout its whole thickness or only upon the surface. The pressure may be kept up to the height stated for eight, twelve, or twenty-four hours, or even longer; but when the Woods have been suiiiciently treated for the purpose for which they are required they are cooled down, the mixture is turned off into some special receptacle, and the woods are taken from the receptacle A, having been rendered more dense, harder, and having been permanently improved in their tints. They may then be cleaned and treated in accordance with the use for which they are intended, or may be piled up for drying, which will speedily take place.

The cost of preparing Woods by this process is very slight. For deals of one inch in thickness the cost is about two German pfennigs per square foot.

The device shown in Sheet 2 is more simple, consisting of a simple tank or reservoir suited to receive the wood and the mixture, with a grate underneath for the direct application of a tire to the bottom.

Vith this apparatus the boiling must be kept up from one to four days, according to the quality of the wood or the thoroughness of the action of the mixture thereupon, and during` this time fresh supplies of the mixture should be added at proper intervals in order to obtain a good result. The result of increased density and solidity will be apparent, even before the Woods are dry, upon sawing them across at the ends, the effect being shown by the depth of the change in the tint, but when the woods are dried the eect is more marked in the in- IOO The described process of treating wood, consisting in saturating the same with a mixture 15 of lime-water and urinein a heated state, substantially as described.

In testimony whereof I have signed my naine to this speeieation in the presence of two subscribing;` witnesses.

J. D. FRANGKS.

Witnesses WILLIAMS C. Fox, Jons. KRACKE. 

